Forum Discussion

RVhiker's avatar
RVhiker
Explorer
Feb 27, 2015

Consequences of reversed polarity

Today my EMS (Progressive Industries, 30 Amp, hard wired) detected a reversed polarity condition at the 30 amp outlet on a campground power pedestal. I plugged into the 50 amp plug using a 50 to 30 amp dogbone and all is well.

However, I'm trying to understand the potential consequences of such a reversed polarity condition. One dangerous consequence would be if a neutral wire touched a metal piece, that piece would be energized with 120 volts. What are the other possible consequences of this condition?

And yes, I reported the reversed polarity condition to the campground office so that some other person won't have an issue.
  • wolfe10's avatar
    wolfe10
    Explorer
    Feb 28, 2015
    Good answers. Yes in the absence of a good ground (an issue in many RV parks in Mexico) stepping from the metal step of the RV to wet grass can give you quite a jolt. It is enough to kill small pets-- sadly have seen it happen to another rig in a park we were in in Patzcuaro several years ago.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Feb 28, 2015
    Wotta bout a neutral to earth ground issue with reversed polarity. You know the neutral carrying UNFUSED current?
  • Bobbo's avatar
    Bobbo
    Explorer II
    Feb 28, 2015
    dbbls wrote:
    I don't know about an RV but I know it is very damaging to a vehicle to have a battery polarity reversed.

    AC circuits and DC circuits are completely different animals. The battery is DC.
  • time2roll's avatar
    time2roll
    Nomad
    Feb 28, 2015
    The chance of hazard increases since everything is hot and the switch breaks the neutral. So you think you switched power off but everything is still hot. Even when a breaker trips power is still available to bite you.

    There is no real polarity while in operation so no damage to a running device.
  • KD4UPL's avatar
    KD4UPL
    Explorer
    Feb 28, 2015
    Just reversed AC polarity won't cause any problems at all. Reversed AC polarity combined with a broken ground will cause a shock hazard.
  • WyoTraveler's avatar
    WyoTraveler
    Explorer
    Feb 28, 2015
    dbbls wrote:
    I don't know about an RV but I know it is very damaging to a vehicle to have a battery polarity reversed.


    Probably wasn't decribed exactly correct since AC changes polarity 60 times a second but pedastal incorrectly wired apparetly tge problem.
  • dbbls's avatar
    dbbls
    Explorer
    Feb 28, 2015
    I don't know about an RV but I know it is very damaging to a vehicle to have a battery polarity reversed.
  • DrewE's avatar
    DrewE
    Explorer II
    Feb 28, 2015
    It's unlikely to cause any major problems with electrical devices, but could be a safety concern if something else breaks. As you surmised, if you have a neutral-ground fault simultaneously with an open ground, you could end up with a hot skin condition. If you have some appliance or other electrical device with a polarized plug, the lines will be reversed; in the case of a table lamp, say, the threaded part the socket will be hot (and unswitched), while the button in the bottom will be neutral, rather than the other way around.

    It's certainly something worth being corrected, but not really something worth lying awake all night worrying about.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,190 PostsLatest Activity: Jan 23, 2025